The present invention relates to an optical device for reducing Speckle noise according to claim 1.
Such an optical device for reducing Speckle noise of laser light comprises at least first optical element that acts as a diffusor, i.e., scatters light, and that extends along an extension plane as well as an actuator means designed for oscillating said first optical element along said extension plane.
An optical device of the afore-mentioned kind is often used with laser light in order to suppress Speckle noise, which is an interference pattern that is created on the screen (objective speckles) or the retina of the human eye (subjective speckles) due to the high coherency of the laser light.
Such a reduction can be accomplished by letting the light or laser beam pass through or reflect on a moving/oscillating diffuser. In case the frequency is high enough, the human brain integrates the perceived light over time which reduces the perceived speckle noise significantly. Such an optical device is for instance disclosed in US 2011/0043768 which describes a magnet-coil based moving diffuser with complex springs as well as in WO2010078662 which relates to a movable diffuser based on an actuation by means of electroactive polymers